This invention relates generally to efficient, supersonic, laminar flow aircraft wing configurations. More specifically it concerns improvements in the following configuration areas:
a) strake,
b) raked wing tip,
c) reversed fillet wing-strake junction,
d) inboard leading edge flap,
e) hybrid plain-split flap.
Certain prior Richard Tracy patents disclose a laminar flow wing for efficient supersonic flight (U.S. Pat. Nos. 5,322,242, 5,518,204, 5,897,076 and 6,149,101). Recent developments have led to five areas of improvement, principally benefiting low speed characteristics of aircraft using the wing. The wing described in the prior Tracy patents has a sharp, modified biconvex airfoil, with less than about 30 degrees leading edge sweep in order to maintain an attached shock at supersonic cruise conditions, and thickness-chord ratio (t/c) of about 2% or less as a span-wise average over the majority of the wing. The latter excludes a zone near the inboard end, which may be thicker, up to about 4% t/c in combination with fuselage area ruling.
There are several unique characteristics of the supersonic laminar flow wing which pose challenges, especially in low speed flight. These include its sharp leading edge which causes a separation “bubble” at almost any angle of attack in subsonic flight, its extremely thin airfoil which imposes a structural weight penalty as aspect ratio is increased, and the un-swept leading edge which limits the effectiveness of “area ruling” the wing-body for minimizing supersonic wave drag. These (and other characteristics) are unique to the supersonic laminar wing and are substantially mitigated by the herein claimed improvements, acting individually or together, in combination with this type of wing.